TONER, METHOD FOR MANUFACTURING TONER AND METHOD AND UNIT FOR FORMING IMAGE

摘要

PURPOSE: Toner is to inexpensively provide high image density, high tolerance and an excellent image, by using toner for developing a superior electrostatic image having a predetermined precise grain size. CONSTITUTION: Toner including a coloring agent has the following characteristics. The diameter is from 5 micrometer to 12 micrometer. Regarding 90 percent of the toner as an accumulation value based upon the number of grains not smaller than 3 micrometer, a in the formula(1) is not greater than 0.900. The formula(1) is a=Lo/L wherein Lo is an outer circumference length of a circle having the same projection surface as the grain and L is an outer circumference length of the grain. A correlation between a cut rate Z and a diameter of the toner X satisfies the formula(2). The formula(2) is Z <= 5.3xX. The formula(3) is Z=(1-B/A)x100 wherein A is grain density of the whole measurement particles measured by using a grain analyzer and B is density of measurement particles having the same size as grains not smaller than 3 micrometer. A correlation between an accumulation value based upon the number of grains of which a is not smaller than 0.950 and a diameter X satisfies the formula(4). The formula(4) is Y>= exp5.51xX¬-0.645 wherein the diameter X is from 5.0 to 12.0 micrometer.